Problem: Simplify the following expression: ${-9(1-k)+2(-2k-5)}$
Solution: Distribute the ${-9}$ into the first set of parentheses: $ {-9(}\gray{1-k}{)} + 2(-2k-5) $ $ {-9+9k} + 2(-2k-5) $ Distribute the ${2}$ into the parentheses: $ -9+9k + {2(}\gray{-2k-5}{)} $ $ -9+9k {-4k-10} $ Rewrite the expression to group the ${k}$ terms and numeric terms: $ {9k - 4k} {-9 - 10}$ Combine the ${k}$ terms: $ {5k} {-9 - 10}$ Combine the numeric terms: $ {5k} {-19}$ The simplified expression is $5k-19$